4 of 4 adjusted title to reflect question in body; fixed section link; removed unnecessary edit note and meta-commentary; edited tags

How do the Cleric and Druid's Spontaneous Casting interact with other classes' spells?

This is a very RAW vs. RAI question.

When the descriptions of both clerics and druids discuss how prepared spells are instead converted into specific kinds of spells, they always talk about "a" or "any" prepared slot.

For the Cleric:

The cleric can “lose” any prepared spell that is not an orison or domain spell in order to cast any cure spell of the same spell level or lower

For the Druid:

She can “lose” a prepared spell in order to cast any summon nature's ally spell of the same level or lower.

If I were playing an 8th-level wizard / 1st-level druid / 1st-level cleric, according to the wording of their class abilities I should be able to convert the higher-level wizard spells into either cure or summon nature's ally spells.

  1. Has Paizo ever confirmed that this does or does not work this way?
  2. Is this right by RAW?
  3. Should this be allowed? This is obvious with a no.